From nobody Wed Dec 17 06:00:30 2025 Received: from mail-pf1-f202.google.com (mail-pf1-f202.google.com [209.85.210.202]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id DD21B221544 for ; Fri, 4 Apr 2025 19:39:54 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=209.85.210.202 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1743795596; cv=none; b=UxZ3enuLgC46klGNJBo+pUoW1hIShN3sl17WmlVDdKWsWQE5Wo6HT2X0TiW6CxhFfSvzS0+fyx+Fx5tAFOzZi+tBen+d8luRm4RKh8YC/wl2he6hu5kLopOJdP1MoEvGTWuuAKHlvcbE9q9/pc7pwUHHWwo9CRb97J4t0rduSTI= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1743795596; c=relaxed/simple; bh=zvROXmjtL1IIWkXeJFgdhMrAr1KnWI1Z/K2ADvFL0ug=; h=Date:In-Reply-To:Mime-Version:References:Message-ID:Subject:From: To:Cc:Content-Type; b=TBLVgApWn7NIpYUlaMCCvl1w1f69Qk2zz9Fxe+lhd9HvVt4I/waUTosOqmAzReBzKIE2a5Y1ZzSrV2Sk6Cfir8z4qJRuLgUp3cCvIFh96RnVh7WtPT+6RvX6QTBywLtIeV240qcG/1Fo2XbD4rRV+W+97B7xmqvviQJCuSzQxVY= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass (p=reject dis=none) header.from=google.com; spf=pass smtp.mailfrom=flex--seanjc.bounces.google.com; dkim=pass (2048-bit key) header.d=google.com header.i=@google.com header.b=axIjS05k; arc=none smtp.client-ip=209.85.210.202 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=reject dis=none) header.from=google.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=flex--seanjc.bounces.google.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=google.com header.i=@google.com header.b="axIjS05k" Received: by mail-pf1-f202.google.com with SMTP id d2e1a72fcca58-736d64c5e16so2096867b3a.3 for ; Fri, 04 Apr 2025 12:39:54 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20230601; t=1743795594; x=1744400394; darn=vger.kernel.org; h=cc:to:from:subject:message-id:references:mime-version:in-reply-to :date:reply-to:from:to:cc:subject:date:message-id:reply-to; bh=RGxOMNtpRYtvYPUfMG5TmBHR1pFGxtORoL82B7xlqeE=; b=axIjS05k0wlvUfolX7qcCU9p6AiPh/ykag8O7FX5ExQy2znj+Xqtt9ME/buLrKrVTr kRpKpLx46gQdCIR2D+RI9nfESn5bDTl4RFaYlsn/tn43pRI4qrXD+pBlwCZREsEyzNt1 vGZLPqRx+NyynVKeN67l2Mcl9SNtSCUKT09tGzx2T06zcTpnYLDZIg4b2gBX+nV7GLS/ E89tyA3i60KKk9s2EyFbSA4kUL6rf0bCFBzLm8Yx2j81aGuHxrs08ZaanW7vofwLzc9d KiGbYjNeGoxM0bu7YwQbWhBIoB27IX5tTQPwv3vqKpaAIY05S2iaRhCuWmt0FDDqlCAc ZUQw== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1743795594; x=1744400394; h=cc:to:from:subject:message-id:references:mime-version:in-reply-to :date:reply-to:x-gm-message-state:from:to:cc:subject:date:message-id :reply-to; bh=RGxOMNtpRYtvYPUfMG5TmBHR1pFGxtORoL82B7xlqeE=; b=GGPw/HXnm7DtVPsxrpFhFrGjPnb3UFalShGOrbrXJNvUwdXaR2p79rNCjZTUnvRZUd FqbS+bylSVMzMsGLk6FXl/s6NJrMiWUr4mH30TrIoRYztach2dCkwFLjh9AJKbSiVvm9 aKeDrYNGQbPxKSDzYc9+XsKnC8o//dmqS0I8Mtam3tIee80B6LFpafOHPwVQYOUEdTEQ pQd7ssyD49WyPLC7pqI/Wa0YdP54Lj1tP1rfVoMYliYGigNKdHej84EOojB0t4EJXht4 hggzQ19JSNmEfxf1Ru2MfKTTU95brxkoTHKIRuMHQxeYPQ9QO9imjEQd23clkEiVLd7E tc+Q== X-Forwarded-Encrypted: i=1; AJvYcCVUxch/5W3rC2+XkImT0eHgumgLqIZTJfAjB20Xf46S9/dmF+fibcovLUgDXK41C7+kVxwBXqomiesVzRo=@vger.kernel.org X-Gm-Message-State: AOJu0YxIks6O4qB/G7Z/P24T23/LXhLntANJhroYzXcrKh62566VUV9q 3VeORFzlp4xNRfRA1ZbceDMIlLfxXHjWU5HXRa0nwI3IKDLgQruzLIPscx0KOLnShKd6aHNexe7 e/w== X-Google-Smtp-Source: AGHT+IEQIRfv5MQyN5FPXlDH0jiZdTHciPaHWXw+Tn7fs2rQ/C2nsY1CH5202uPXIoXMn1X9vHNvV8pVCeI= X-Received: from pfbfa9.prod.google.com ([2002:a05:6a00:2d09:b0:739:8cd6:c16c]) (user=seanjc job=prod-delivery.src-stubby-dispatcher) by 2002:a05:6a00:2442:b0:736:6ac4:d204 with SMTP id d2e1a72fcca58-739e4855dd7mr5053725b3a.11.1743795594255; Fri, 04 Apr 2025 12:39:54 -0700 (PDT) Reply-To: Sean Christopherson Date: Fri, 4 Apr 2025 12:38:19 -0700 In-Reply-To: <20250404193923.1413163-1-seanjc@google.com> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: Mime-Version: 1.0 References: <20250404193923.1413163-1-seanjc@google.com> X-Mailer: git-send-email 2.49.0.504.g3bcea36a83-goog Message-ID: <20250404193923.1413163-5-seanjc@google.com> Subject: [PATCH 04/67] KVM: x86: Take irqfds.lock when adding/deleting IRQ bypass producer From: Sean Christopherson To: Sean Christopherson , Paolo Bonzini , Joerg Roedel , David Woodhouse , Lu Baolu Cc: kvm@vger.kernel.org, iommu@lists.linux.dev, linux-kernel@vger.kernel.org, Maxim Levitsky , Joao Martins , David Matlack Content-Transfer-Encoding: quoted-printable Content-Type: text/plain; charset="utf-8" Take irqfds.lock when adding/deleting an IRQ bypass producer to ensure irqfd->producer isn't modified while kvm_irq_routing_update() is running. The only lock held when a producer is added/removed is irqbypass's mutex. Fixes: 872768800652 ("KVM: x86: select IRQ_BYPASS_MANAGER") Cc: stable@vger.kernel.org Signed-off-by: Sean Christopherson --- arch/x86/kvm/x86.c | 17 +++++++++++++++-- 1 file changed, 15 insertions(+), 2 deletions(-) diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c index f94f1217a087..dcc173852dc5 100644 --- a/arch/x86/kvm/x86.c +++ b/arch/x86/kvm/x86.c @@ -13569,15 +13569,22 @@ int kvm_arch_irq_bypass_add_producer(struct irq_b= ypass_consumer *cons, { struct kvm_kernel_irqfd *irqfd =3D container_of(cons, struct kvm_kernel_irqfd, consumer); + struct kvm *kvm =3D irqfd->kvm; int ret; =20 - irqfd->producer =3D prod; kvm_arch_start_assignment(irqfd->kvm); + + spin_lock_irq(&kvm->irqfds.lock); + irqfd->producer =3D prod; + ret =3D kvm_x86_call(pi_update_irte)(irqfd->kvm, prod->irq, irqfd->gsi, 1); if (ret) kvm_arch_end_assignment(irqfd->kvm); =20 + spin_unlock_irq(&kvm->irqfds.lock); + + return ret; } =20 @@ -13587,9 +13594,9 @@ void kvm_arch_irq_bypass_del_producer(struct irq_by= pass_consumer *cons, int ret; struct kvm_kernel_irqfd *irqfd =3D container_of(cons, struct kvm_kernel_irqfd, consumer); + struct kvm *kvm =3D irqfd->kvm; =20 WARN_ON(irqfd->producer !=3D prod); - irqfd->producer =3D NULL; =20 /* * When producer of consumer is unregistered, we change back to @@ -13597,12 +13604,18 @@ void kvm_arch_irq_bypass_del_producer(struct irq_= bypass_consumer *cons, * when the irq is masked/disabled or the consumer side (KVM * int this case doesn't want to receive the interrupts. */ + spin_lock_irq(&kvm->irqfds.lock); + irqfd->producer =3D NULL; + ret =3D kvm_x86_call(pi_update_irte)(irqfd->kvm, prod->irq, irqfd->gsi, 0); if (ret) printk(KERN_INFO "irq bypass consumer (token %p) unregistration" " fails: %d\n", irqfd->consumer.token, ret); =20 + spin_unlock_irq(&kvm->irqfds.lock); + + kvm_arch_end_assignment(irqfd->kvm); } =20 --=20 2.49.0.504.g3bcea36a83-goog